Unless otherwise indicated, Andes will assume an angle is in radians. For Andes to recognize a trig function in terms of angles in degrees, you need to specify that it is in terms of degrees using one of the following formats:

sin(20 deg)  
cos(30 deg) 
v_x = v * cos(qv - 37 deg)

Andes also permits the parentheses to be omitted around the argument of a trig function:

sin20 deg
sin 20 deg
cos30 deg 
cos 30 deg